﻿<%@ Application Language="C#" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Data" %>
<script runat="server">

    
 protected void Application_Start(object sender, EventArgs e)
{
    Application["user"] = 0;
    Application["count_visit"] = 1;
 
}
 
protected void Session_Start(object sender, EventArgs e)
{


    Session["Username"] = "";
    Session["User"] = null;
    Application.Lock();
    Application["user"] = (int)Application["user"] + 1;
    Application.UnLock();
    int count_visit = 0;

    //Kiểm tra file count_visit.txt nếu không tồn tại thì         
    if (System.IO.File.Exists(Server.MapPath("count_visit.txt")) == false)
    {
        count_visit = 1;
    }
    // Ngược lại thì      
    else
    {
        // Đọc dữ liệu từ file count_visit.txt    
        System.IO.StreamReader read = new System.IO.StreamReader(Server.MapPath("count_visit.txt"));
        count_visit = int.Parse(read.ReadLine());
        read.Close();
        // Tăng biến count_visit thêm 1      
        count_visit++;
    
    }

    // khóa website         
    Application.Lock();

    // gán biến Application count_visit     
    Application["count_visit"] = count_visit;

    // Mở khóa website    
    Application.UnLock();

    // Lưu dữ liệu vào file count_visit.txt     
    System.IO.StreamWriter writer = new System.IO.StreamWriter(Server.MapPath("count_visit.txt"));
    writer.WriteLine(count_visit);
    writer.Close();
 
}
 
protected void Session_End(object sender, EventArgs e)
{
    Application.Lock();
    Application["user"] = (int)Application["user"] - 1;
    Application.UnLock();
    Session.Clear();
    Session["User"] = null;
  
}

protected void Application_End(object sender, EventArgs e)
{
    Session.Clear();
} 
</script>